Important Notice:

Practice-It will be discontinued as of November 1st, 2024. After this date, the website will remain online for a transitional period, but login will be restricted to University of Washington NetID authentication. This marks the next phase towards the platform's full retirement. Thank you for your use and support of the application over the years.

If you are looking for an alternative, a similar tool, CodeStepByStep, was developed independently by the original author of Practice-It, and is available at codestepbystep.com**

logo Practice-It logo

Main Page → Problems → Solve a Problem

BJP5 Exercise 15.22: fromCounts

Related Links:
Author: Marty Stepp (on 2019/09/19)

Write a method called fromCounts that constructs and returns a new ArrayIntList of values given an existing ArrayIntList of counts. Assume that the ArrayIntList that is passed as a parameter stores a sequence of integer pairs that each indicate a count and a number. For example, suppose that an ArrayIntList called list stores [5, 2, 2, -5, 4, 3, 2, 4, 1, 1, 1, 0, 2, 17]. We will interpret this sequence of pairs to mean that you have 5 occurrences of 2, followed by two occurrences of -5 followed by 4 occurrences of 3, and so on. So the call of: 

            ArrayIntList list2 = list.fromCounts();

should cause the variable list2 to store [2, 2, 2, 2, 2, -5, -5, 3, 3, 3, 3, 4, 4, 1, 0, 17, 17].

Assume you are adding to the ArrayIntList class with following fields: 

public class ArrayIntList {
    private int[] elementData;
    private int size;

    // your code goes here
}
Type your solution here:


This is a partial class problem. Submit code that will become part of an existing Java class as described. You do not need to write the complete class, just the portion described in the problem.

You must log in before you can solve this problem.


Log In

If you do not understand how to solve a problem or why your solution doesn't work, please contact your TA or instructor.
If something seems wrong with the site (errors, slow performance, incorrect problems/tests, etc.), please

Is there a problem? Contact a site administrator.